Blackmail, or more precisely, extortion, is an act that threatens civilians with egregious harm to pressure their state or nonstate government to bring an end to war and/or deter them from war in the future. It is not foreign to armed conflict. In asymmetric war, the problem is particularly acute because each side's ability to solely target military objects is limited. When guerrillas cannot reach military targets and choose to target mixed or civilian targets instead, they face fierce condemnation. The stronger parties, too, face a similar problem and similar condemnation. When they exhaust their bank of military targets, their hands seem tied regardless of the intensity of the threat they confront. Each side asks how to continue fighting when military targets are either inaccessible or are few and far between. In each case, they turn to civilian targets.

In conventional war, soldiers, regardless of the role they play, are fair game. Civilians, regardless of the threat they pose, are not. There are many good reasons for adhering to this convention. For many nations, it protects their civilians from excessive harm and pushes the field of battle away from population centers. “Thanks to this convention,” writes Yitzchak Benbaji, “the soldiers' family members are safer, released soldiers would have safer places to return to, and wounded soldiers would have protected healing spaces.” This is probably true, assuming we are talking about the Western Front circa 1917.